The Carolina Panthers' quarterback sustained a concussion that he could have and should have avoided on a play that was both infuriating and remarkable. Newton did something he had explicitly said he would never do again. And by doing so he put his own brain — and the Panthers' season — at extreme risk.

With the Panthers down by 18 points early in the fourth quarter of what would eventually become a 48-33 loss to Atlanta, Newton was trying to run the ball in for a two-point conversion. For once, on an afternoon filled with frustration for Carolina, the play actually worked. A hole opened on the left side. Newton darted through it and looked like he would score easily.

And then he slowed down.

Call it gamesmanship. Or showboating. Or just bad awareness. But if he had stayed at full speed, Newton would have run into the end zone either untouched or only having to absorb a glancing blow.

Instead, by slowing down, the quarterback allowed Atlanta linebacker Deion Jones to smash into him with a helmet-to-helmet hit that you could hear in the top row of the stands at the Georgia Dome.

That was the infuriating part — Carolina's best player got hurt on a play that never should have occurred. Newton had already gotten a taunting penalty in the game. The slowdown looked an awful lot like Newton trying to taunt somebody again — despite being down by 18.

And here was the remarkable part — while Newton buckled from the hit, he somehow kept his balance, reset himself and dove to successfully reach the ball over the goal line. The conversion, somehow, was good.

But Newton's brain was not.

That play, with 11:42 left in the game, would be the last for Newton. He would go to the locker room shortly after that and be diagnosed with a concussion.

Head coach Ron Rivera, though, was asked if Newton could have avoided the hit by simply traveling at full speed into the end zone.

"Probably," Rivera said.

Look, no one ever deserves a concussion. But Newton does knows better than this.

Let's flash back to last December. At New Orleans, Newton was running for the end zone and was about to score — but he slowed down to enjoy the moment. Saints linebacker Michael Mauti leveled him at the 1, knocking him out of bounds. Again, it is a helmet-to-helmet hit.

Newton — who never missed a play in that game — would later tell the media that he had told a Panthers team doctor he deserved the shot from Mauti.

"I deserved to get hit like that, taking that foot off the gas," Newton said then. "But it won't happen again, any time I get an opportunity to score."

It won't happen again. And yet it did happen.

Just like in New Orleans, Newton was evaluated for a concussion. That time he didn't have one

This time he did.

Newton will have to go through the concussion protocol before he can return. The Panthers — whose medical staff is already under review by the NFL and the NFL Players Association for its handling of Newton following an enormous hit he took at Denver in Week 1 — will be very careful with the franchise.

There's no telling how Newton's brain will respond to what happened Sunday.

But what we do know is that Newton took an enormous hit he did not have to take. And with that one bad decision by the NFL's reigning MVP, the Panthers' entire season may have taken an enormous hit as well.